Mechanical stoker.



2 SHEETS-BREST l.,

lll/Am E Iii W. M. DUNCAN.

MECHANICAL STOKER.

AIPLIGATION FILED APB.8. 1912. l

' Patented Mar. 3, 1914.

.v2 SHEETS-SHEET 2.

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. l. WMI) man Q. mw'

" To-all 'whom may concern WILLIAM 1a. DUNCAN',

.oF AIiToN, ILLINo'IS.

V MECHANICAL STOKER.

Specification of Letters Patent.

Patented Man',

Application lled April '8, 1912. Serial No. 689,214.

' Be it known that I, WILLIAM M. DNC'AN," a citizen ofthe United States of America, and resident of Alton, in the county f Madison'and State of Illinois, have invented certain v,new and useful Improvements in Mechanical Stokers, of Whichthel following is .a full, clear, and exact description, reference being had to'theraccompanying drawings, forming a part of this specification.. v

" My invention .relates to mechanical stok,

ers l for furnaces and,"` more particularly" stated, comprises adjustable means ,whereby y .versely across the stoker... WVater is-delivthe fuel resting uponthe traveling grate at the rear end -of 'a mechanical AStoker may be retained upon the grate for. thorough 'consumption 'insteadof being discharged over the tail end of thestoker before all of the combustible'matter present 4therein has been consumed.

Briefly stated, the improvemntconsists 4in an adjustable retardation device, preferably includinga water back,-loca`ted above the rear end of a stolzer and serving to produce a bank of ashes. and other residue of combustion upon a traveling grate in such manner as to cause the fuel in front of the bank to be held on the grate until complete combustionhas taken place. 4 .Permissible adjustment of the retardation device produces a gap betweenthe'traveling grate andthe retardati'on device through which the residue from lthe fuel is 'discharged over thetail of the-grate whenever such dischargebecomes' necessary or advisable.4 l l. y

, Figure I is a view partly'in-elevation` andev partly in vertical longitudinal section of al portion of a furnac'e, the rear end of" a stolter, and my retardation device. lFig'. II isa vievv partly in elevation and partly in verticalcross sectionof my retardation device and thesupporting members in which said-4 device ismovable. Fig. III is an enlarged elevation of the retardation device as viewed from one side of the furnace' in which itis used. v -In the drawings Aldesignates Athe side yWalls of a furnace, and B the frame vof a Stoker located in the combustion chan'iber of the furnace, the stoker belng provided with la traveling grate C of any usual cnistruc.-l

tion.v

My retardation device is located above the rear 4portion of the stoker C and is som'ounted'as to normally occupy a position in which it is very slightly removed rom the fueland "residue carrying portion of the traveling` grate C, and from which position it is removable aivay from the grate, preferably in a rearward direction, for the purposerofproducing' agap between the retardation device 'andthe ,errate that'wilvl allowresidue from 4th'e fuel that has been restrained in front of 'the retardationdevice to bedischarged over the tail'encl of t-hestoker.

The retardation device in its preferred formcomprises a water back 1 thatmay be in the form of atubular roller, as illustrated in the drawing'ayand which extends'transered to and 4dischartgedx from the water back through.condu'ctlngr 'pipesQ united t`o the former by couplings 3, which are designed to be rotated .on the horizontal portions 2 of the. conducting 'pipes 2. To provide for lthe rearward and foi'wvardinovelnent'of the Wa-` ter back-1, said water back haslsecln'ed t-o it hand lwheels 4|. furnished Witlillandle arms 5 thefwaterback from itsnorrnal. position toA l an innorniahposition.

7 designates housing `'boxe-s mounted in the l furnace Walls Aan'd in 4which lt-he water back- -1 may-be adjustedfby"rolling it vto and'fro for' thefpurpose ofproducng or varying-the gap between said water back and the -stoker grate. These boxes serve as bearers for the racks'S with `which the spur gears .6 of 'the' hand wheels 4 have eiiffavelnent. The housing boxes 7 .arerpreferably elongated. in .av4

horizontalgdirection'and the racks 8 support tally, or substantially *parallel withfhe top surface of the stokerC. j It u'illbe apparent that' vwhen the parts thus mentioned are art ranged'as stated, the water back' may-bei rolled backwardly and forwvz'irdiy in -substan 'ed thereby arel preferably arranged horizontially a horizontal plane, thereby providing l for the waterback being normally positioned directly over the portion of the t1a \'cl1ng grate that supports the residue of fuel-at the rear end of the Stoker toa rear position that will produce' agap 'through which the resi-rv due maybdischarged over the tail 0nd of the stoker, y Itfwill be 'obviousthat inasmuch as the Water back lisadjustable to and fro within thaelngated boxes, and is eoanectecl'to theconductin pipe connections and means for operating it 'exterior of the lui-nace, 1t 1s `advisable vto provide some means for' pre` venting the escape fmair through said boitesI trom the combustionChamber inthe furnace.

The means I prei-'ide for this' purpese 1re guard plates 9 fitted around the Water back, and extending through lsuitable guidewziys in the boxes 7 .in which thejr slide when the 'water beek is being'4 adjusted. A

' It'willbe apparent that thedesired rolling'- movein'ent of thev Water back inay be acc'oniplished withoutinterfering-With the Water.

back pipes by furnishing flexible connet-ione between the Saud Water pipes and thelineim which the' fuelrestfing upon the grate be i'ezstrain'ed While .the grate is'in'inoti'on,

and means for rolling' Said-barrier b'acknd forth to vary ,thegap between the grate'and 'the barrier.

Q.- The -oinbnation with a1 "mechanical Stoker having a traveling' grate, of@ rcylin .dricnl Water' backatlthereer of-said grate,

Water `eoncluet.ng c onmeeti0nsI to which said Water back is journaled, and means-for 1011- 'ing saiciw'ateibaek back and forthjto vary the gap between the gra-tenuti bar-mer..

YVI-LLIAM M. DUNCAN; '[n the v presence of?` A.'B. STRATTQN, A. R. 'CROSSMAN. 

